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Publication Date: 2016-Aug-05

Publishing Venue

The Prior Art Database


A subsea assembly alignment tool for aligning an upper subsea assembly having a receiver with a lower subsea assembly having a mandrel while avoiding undesirable contact between the lower subsea assembly and any portion of the upper subsea assembly extending below the bottom of the receiver.

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Subsea Assembly Alignment Tool

Background [0001] This section is intended to introduce the reader to various aspects of art that may be related to various aspects of the presently described embodiments. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the described embodiments. Accordingly, it should be understood that these statements are to be read in this light and not as admissions of prior art.

[0002] In the oil and gas industry, a well may be drilled and a completion system may be installed at a surface end of the well in order to extract oil, natural gas, and/or other subterranean resources from the earth. Such completion systems may be located onshore or subsea, depending on the location of the desired resource and/or well. A completion system generally includes a wellhead assembly through which a resource is extracted or fluids injected. Such systems also may include a wide variety of other components or assemblies, such as various housings, trees, casings, hangers, valves, fluid conduits, and the like, that may be used to control extraction operations.

[0003] A tubing hanger may be installed in a completion system to support production tubing through which production fluids may be produced, injection tubing through which fluids may be injected, or other pipe or "tubing string" through which fluids may flow. The tubing hanger may be installed in or at the top of the wellhead assembly, within a casing hanger, or landed within a tubing spool, adapter spool, or production or injection tree, for example. The tubing string may include an internal fluid passageway or bore, for example a production bore that extends into the production zone of the well to produce hydrocarbons from the well or to inject treatment fluids into the well.

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[0004] A subsea completion system may include one or more subsea assemblies installed above the wellhead assembly. Such subsea assemblies may include, for example, a tree assembly, a spool assembly, and/or any other subsea assembly for fluid production or injection or control. Various arrangements of control valves may be coupled to a wellhead in a subsea assembly, such as without limitation a spool, an adapter, a vertical tree, a horizontal tree, or a hybrid, convertible, flexible, and/or modular tree, for example a tree that may include attributes of a horizontal tree and a vertical tree at the same or at different times.

[0005] In order to be installed above the wellhead to enable fluid communication between wellhead and surface, the subsea assembly must be aligned with the wellhead. Alignment may be assisted by a diver or may be diverless, e.g. by way of a remotely operated vehicle (ROV) or autonomous underwater vehicle (AUV), and may be performed with or without guidelines extending between subsea well structure and surface. Guidelineless systems may be used in deep water...